CN111752146A - Dead time estimating device and testing device provided with same - Google Patents
Dead time estimating device and testing device provided with same Download PDFInfo
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- CN111752146A CN111752146A CN202010223725.2A CN202010223725A CN111752146A CN 111752146 A CN111752146 A CN 111752146A CN 202010223725 A CN202010223725 A CN 202010223725A CN 111752146 A CN111752146 A CN 111752146A
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- G05B13/00—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion
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Abstract
Provided are a dead time estimation device and a test device provided with the same, which can estimate dead time in a control system with high precision. The dead time estimation device (6) is provided with a dead time calculation unit (64) for setting the frequency characteristic of an element obtained by removing a dead time element from the transfer function of the control object (P) to G ^ e/e‑L^′1sAnd a useless time calculation unit (64) for calculating useless time L ^ 1 for minimizing the value of the evaluation function J of the formula (1) when the transfer function of the controlled object (P) not including the useless time element is G ^ 1.
Description
Technical Field
The present invention relates to a dead time estimation device for estimating a dead time of a control target and a test apparatus provided with the same.
Background
It is known that, when a control target is controlled, a command actually input to the control target is delayed from an input command due to a sampling period, communication in a control device, and the like. This delay is generally referred to as dead time. This dead time is known to affect the control of the control target.
For example, in the PID control, the responsiveness may not be improved due to the influence of dead time.
In order to improve the responsiveness of the control, for example, in the control device disclosed in patent document 1, on the input side of the operation amount calculation means for calculating the operation amount to the control target based on the target value and the feedback value, dead time compensation control is performed in which the output of the dead time compensator is given. That is, in the control device, at the time of the target response, the dead time compensation control by the so-called smith compensation method is performed.
This makes it possible to quickly bring the response value of the controlled object to the target value and suppress the occurrence of overshoot.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open publication No. 2003-167605
Disclosure of Invention
Problems to be solved by the invention
In addition, when the dead time compensation control is performed as described above, it is important to estimate the dead time of the control target with high accuracy. That is, in the case of performing the dead time compensation control described above, since the feedback value is adjusted in accordance with the dead time of the control target, if the dead time has an error, the control performance of the dead time compensation control is affected.
The accuracy of estimation of dead time is important not only in the dead time compensation control described above but also in other control system designs affected by dead time, because it affects control performance.
The invention aims to provide a dead time estimation device capable of estimating dead time of a controlled object with high precision.
Means for solving the problems
A dead time estimation device according to an embodiment of the present invention is a dead time estimation device that estimates a dead time of a control target. The dead time estimating device includes a dead time calculating section for setting a frequency characteristic of an element obtained by removing a dead time element from a transfer function of the control object to G ^ e-L^′1sAnd setting the transfer function of the controlled object not including the useless time element as G-lambada, and calculating the useless timeThe value of the evaluation function J of the formula (1) is minimized, and the useless time L ^' 1 (the first structure) is obtained.
[ numerical formula 1]
This makes it possible to estimate the dead time of the control target with high accuracy. That is, the dead time in which the value of the evaluation function is minimized is obtained in the evaluation function of expression (1) in which the frequency characteristic of the element obtained by removing the dead time element from the transfer function of the control target and the transfer function excluding the dead time element are used as variables, respectively, whereby the dead time of the control target can be estimated with high accuracy.
Therefore, by controlling the control target using the dead time estimated by the dead time estimation device, the control target can be controlled by the designed control system while suppressing the influence of the estimation error of the dead time.
In the first configuration, the dead time estimation device includes: a dead time initial value acquisition unit that obtains a dead time initial value of the control target; and a frequency characteristic acquisition unit that obtains the useless time element using the useless time initial value, and obtains a frequency characteristic of an element obtained by removing the useless time element from a transfer function of the control target as G ^/e-L^′1s(second structure).
This makes it possible to estimate the dead time of the controlled object in a short time with high accuracy. That is, since the dead time initial value acquiring unit can obtain, as the dead time initial value, a value closer to the true value of the dead time to be controlled, the dead time initial value with higher accuracy can be used as the dead time considered by the above expression (1) used for the calculation by the dead time calculating unit. Thus, the dead time of the control target can be quickly obtained by the dead time calculation unit.
In the second configuration, the dead time calculation unit obtains the dead time L ^' 1 (third configuration) which is within a predetermined range based on the dead time initial value and in which the value of the evaluation function J is minimized.
Thus, even when the dead time initial value is not accurately obtained, the dead time calculation unit can accurately estimate the dead time of the control target.
In the second or third configuration, the dead time estimation device further includes a transfer function acquisition unit that inputs a signal to the control target and acquires a transfer function based on a response result of the signal. The dead time initial value acquisition unit obtains the dead time initial value from a response signal obtained when a predetermined input signal is input to the control target of the transfer function acquired by the transfer function acquisition unit (a fourth configuration).
Thus, even when the dead time initial value cannot be obtained by inputting an input signal to a control target, the dead time initial value can be obtained from a response signal in a case where a predetermined input signal is input to the transfer function after the transfer function of the control target is obtained. Therefore, the dead time initial value of the control target can be obtained with high accuracy.
In the fourth configuration, the dead time initial value acquisition unit obtains, as the dead time initial value, a time until a predetermined threshold value is exceeded with respect to the response signal (a fifth configuration). This makes it possible to easily obtain an initial value of dead time of the control target.
In the fourth configuration or the fifth configuration, the predetermined input signal is a step signal (sixth configuration). This makes it possible to easily obtain an initial value of dead time of the control target by using the step response to the transfer function.
A test apparatus according to an embodiment of the present invention includes: a control target that gives a driving force to the sample; a control device that controls the control object; and a dead time estimating device according to any one of the first to sixth configurations, which outputs the estimated dead time to the control device (a seventh configuration).
Thus, in the test apparatus for a sample, the dead time of the control target for applying the driving force to the sample can be estimated with high accuracy by the dead time estimation device. Therefore, the control target can be controlled by the designed control system, and the test apparatus can be driven with high accuracy.
ADVANTAGEOUS EFFECTS OF INVENTION
In the dead time estimation device according to one embodiment of the present invention, the frequency characteristic of an element obtained by removing a dead time element from a transfer function of a control target is set to G ^ e/e-L^′1sAnd determining a value of the useless time L & ltlambert & gt 1 for minimizing the value of the evaluation function J of the formula (1) when the transfer function of the controlled object not including the useless time elements is set to G & ltlambert & gt'. This makes it possible to estimate the dead time of the control target with high accuracy.
Drawings
Fig. 1 is a functional block diagram showing a schematic configuration of a test apparatus including a dead time estimating apparatus according to embodiment 1.
Fig. 2 is a block diagram of the control device according to embodiment 1.
Fig. 3 is a bode diagram for explaining a difference due to estimation accuracy of dead time in the case of using the control system.
Fig. 4 is a flowchart illustrating an example of the operation of the dead time estimation device.
Fig. 5 is a functional block diagram showing a schematic configuration of a test apparatus including a dead time estimating apparatus according to embodiment 2.
Fig. 6 is a diagram showing an example of a relationship between frequency characteristics measured by inputting a random signal to a control target and a transfer function obtained using an evaluation function.
Fig. 7 is a diagram showing an example of the step response.
Fig. 8 is a diagram showing an example of a step response obtained by comparing an example of an actually measured step response with an example of a step response obtained by using a model.
Fig. 9 is a flowchart illustrating an example of the operation of the dead time estimation device.
Fig. 10 is a block diagram of a control device according to another embodiment.
Description of the reference numerals
1. 101: a testing device; 2. 102: a control device; 3: a motor drive circuit; 4: an electric motor; 5: a torque detector; 6. 60: a dead time estimating means; 10: a feedback loop; 11. 63: a frequency characteristic acquisition unit; 12: an initial value setting unit; 13. 64: a dead time calculation unit; 51: an attenuation ratio adjusting unit; 52: a filter; 61: a transfer function acquisition unit; 62: a dead time initial value acquisition unit; 112: a controller of the feedback system; 120: a feed forward loop; 111. 121: a controller of a feed forward system; p: a control object; m: and (4) sampling.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to the drawings. The same or corresponding portions in the drawings are denoted by the same reference numerals, and description thereof will not be repeated.
< embodiment 1>
(Overall Structure)
Fig. 1 is a diagram showing a schematic configuration of a test apparatus 1 including a dead time estimating apparatus 6 according to embodiment 1 of the present invention in the form of functional blocks. The test apparatus 1 is a test apparatus for testing the characteristics of a sample M such as a motor of an automobile. The sample M to be tested in the test apparatus 1 may be a rotary body other than a motor.
Specifically, the test apparatus 1 includes a control device 2, a motor drive circuit 3, an electric motor 4, a torque detector 5, and a dead time estimating device 6.
The control device 2 generates a drive command for the motor drive circuit 3 using a motor torque command r as an input command and a feedback value described later. The control device 2 includes a feedback loop 10 (see fig. 2) that negatively feeds back the motor torque command r using the output value of the torque detector 5. Since the configuration of the control device 2 for generating the drive command is the same as that of the conventional one, detailed description of the control device 2 is omitted. The structure of the feedback loop 10 is described later.
Although not particularly shown, the motor drive circuit 3 includes a plurality of switching elements. The motor drive circuit 3 drives the plurality of switching elements based on the drive command, thereby supplying electric power to a coil, not shown, of the electric motor 4.
The electric motor 4 has a rotor and a stator, not shown. The rotor rotates relative to the stator by supplying electric power from the motor drive circuit 3 to the coils of the stator. The rotor is coupled to the sample M via an intermediate shaft, not shown, so as to be rotatable integrally with the sample M. Thereby, the electric motor 4 can output torque to the sample M by the rotation of the rotor. The structure of the electric motor 4 is the same as that of a general motor, and therefore, a detailed description of the electric motor 4 is omitted.
The torque detector 5 is provided on an intermediate shaft connecting the electric motor 4 and the sample M. The torque detector 5 detects the torque output from the electric motor 4. The output value of the torque detected by the torque detector 5 is input to the control device 2 as an input value of the feedback loop 10. That is, the output value of the torque detector 5 is used for feedback control. Since the configuration of the torque detector 5 is the same as that of the conventional configuration, detailed description of the torque detector 5 is omitted.
In the present embodiment, the control device 2 has a feedback loop 10 as shown in fig. 2, and the feedback loop 10 feeds back the output value of the torque detector 5 to the motor torque command r as an input command. That is, the test apparatus 1 of the present embodiment controls the driving of the electric motor 4 by a control system including the control device 2, the motor drive circuit 3, the electric motor 4, and the torque detector 5 and not including the sample M.
In fig. 2, r is a target value as a motor torque command, y is an output value of the torque detector 5, and KDIs a differential coefficient, s is a differential element, FdIs the transfer function of the filter 52.
Note that a reference sign P in fig. 2 is a control target, and in the present embodiment, the control target P includes a motor drive circuit 3, an electric motor 4, and a torque detector 5. The control target P also includes a range from the electric motor 4 to the torque detector 5 in the intermediate shaft connecting the electric motor 4 and the sample M. That is, the control object P gives a driving force to the sample M.
The feedback loop 10 is a differential feedback system including a differential element s. The output value of the torque detector 5 is input to the feedback loop 10. The feedback loop 10 has an attenuation ratio adjusting section 51 and a filter 52. The attenuation ratio adjusting section 51 adjusts the attenuation ratio based on the differential element s and the differential coefficient KDTo adjust the attenuation ratio for the control object. The filter 52 excludes the influence of dead time from the output value of the torque detector 5. In the feedback loop 10, the output value of the torque detector 5 is processed by the filter 52 and the attenuation ratio adjusting section 51, and then negatively fed back as a feedback value to the motor torque command r.
In addition, when the control object P is controlled in the test apparatus 1, a delay occurs in the torque input to the sample M with respect to the motor torque command r due to the sampling period, communication, and the like of the control apparatus 2. This delay is called a dead time, and affects the control of the control target P.
Therefore, when designing the control system in consideration of the dead time, it is necessary to estimate the dead time of the control target P with high accuracy and control the control target P using the estimated dead time. For example, when the feedforward control system is designed in consideration of dead time, as shown in fig. 3, when there is an error in the estimated dead time, the feedforward control system has a characteristic different from the designed control performance as shown by a dotted line and a dashed line, as compared to a case where there is no error in the estimated dead time (a solid line in fig. 3).
The dead time estimation device 6 estimates the dead time of the control target P. In the case of the present embodiment, the dead time estimated by the dead time estimation device 6 is used in the filter 52 of the control device 2 in consideration of the influence of the dead time from the output value of the torque detector 5.
In the following description, the numerical expression and "#" in the drawing marked above each character are described after each character to facilitate the expression of the article.
As shown in fig. 1, the dead time estimation device 6 includes a frequency characteristic acquisition unit 11, an initial value setting unit 12, and a dead time calculation unit 13.
The frequency characteristic acquisition unit 11 inputs a random signal (signal) to the control target P to acquire the frequency characteristic G (response result). The random signal is a signal having unpredictable variations. In the present embodiment, a white noise signal is used as the random signal, for example.
The initial value setting unit 12 acquires the useless time initial value L Λ 1 used in the useless time estimating device 6 and the transfer function without the useless time elements. The dead time initial value and the transfer function excluding the dead time element may be stored in a storage unit, not shown, or may be obtained from data input to the dead time estimation device 6.
The useless time calculation part 13 makes the useless time initial value L & ltn & gt 1 acquired by the initial value setting part 12 and the transfer function G & ltn & gt/e & lt the useless time elements-L^′1sRespectively as variables for determining the value of the transfer function G ^ e-L^′1sThe value of the evaluation function J of formula (1) consisting of the frequency characteristic G ^ and the variable is the smallest L ^' 1. Specifically, the dead time calculation unit 13 obtains the optimal solution by a technique such as a simplex method using equation (1).
[ numerical formula 2]
By obtaining the useless time L Λ '1 in the control target P using the formula (1) as described above, the useless time L Λ' 1 can be obtained with high accuracy.
The test apparatus 1 includes the dead time estimating apparatus 6 having the above-described configuration, and thus can accurately estimate the dead time of the control target P for applying the driving force to the sample M by the dead time estimating apparatus 6. Therefore, since the control object P can be controlled by the designed control system, the test apparatus 1 can be driven with high accuracy while suppressing the influence of estimation errors in dead time.
(operation of dead time estimating apparatus)
Next, the operation of the dead time estimation device 6 having the above-described configuration will be described with reference to the flow shown in fig. 4.
When the flow shown in fig. 4 starts, in step SA1, the frequency characteristic acquisition unit 11 of the dead time estimation device 6 inputs a random signal to the control target P. In the next step SA2, the frequency characteristic acquisition unit 11 measures the frequency characteristic G from the output when the random signal is input to the control target P.
Then, in step SA3, the useless time calculation unit 13 converts the useless time initial value L ^ 1 obtained by the initial value setting unit 12 and the transfer function G ^ e without the useless time elements-L^′1sRespectively as variables for determining the value of the transfer function G ^ e-L^′1sThe value of the evaluation function J of the formula (1) described, which is composed of the frequency characteristic G ^ and the variable, is the smallest L ^ 1. Specifically, the dead time calculation unit 13 obtains the optimal solution by a technique such as a simplex method using the above-described equation (1).
Thus, the useless time L & ltn & gt 1 of the control object P can be obtained with high precision.
< embodiment 2>
(Overall Structure)
Fig. 5 shows a schematic configuration of a test apparatus 101 including the dead time estimating apparatus 60 according to embodiment 2 as functional blocks. The test apparatus 101 has the same configuration as the test apparatus 1 according to embodiment 1, except for the configuration of the dead time estimating apparatus 60. Therefore, the same components as those in embodiment 1 are denoted by the same reference numerals, and description thereof is omitted, and only the portions different from embodiment 1 will be described.
In the following description, the numerical expression and "#" in the drawing marked above each character are also described after each character to facilitate the expression of the article.
As shown in fig. 5, the dead time estimation device 60 includes a transfer function acquisition unit 61, a dead time initial value acquisition unit 62, a frequency characteristic acquisition unit 63, and a dead time calculation unit 64.
The transfer function acquisition unit 61 acquires the transfer function G ^ of the control object P from the frequency characteristic G (response result) obtained by inputting the random signal (signal) to the control object P. Fig. 6 shows an example of the frequency characteristic G obtained by inputting a random signal to the control target P with a solid line. The transfer function G Λ is a transfer function used to obtain the useless time initial value L Λ 1 in the useless time initial value obtaining section 62 described later. The random signal is a signal having unpredictable variations. In the present embodiment, a white noise signal is used as the random signal, for example.
The transfer function acquisition unit 61 obtains a transfer function G Λ that minimizes the value of the evaluation function J0 in expression (2). Specifically, the transfer function acquisition unit 61 determines the order of the denominator and the numerator, a, in the general expression of the transfer function shown in expression (3) so as to minimize the value of the evaluation function J0 of expression (2)0～amValue of (a) and (b)0～bnThe value of (c). Fig. 6 shows an example of a calculation result of a transfer function obtained by repeating the calculation when obtaining the transfer function G Λ where the value of the evaluation function J0 is the minimum (calculation example) with a broken line.
[ numerical formula 3]
[ numerical formula 4]
The useless time initial value acquisition unit 62 acquires the useless time initial value L Λ 1 of the control object P using the transfer function G Λ acquired by the transfer function acquisition unit 61. Specifically, the unused time initial value acquisition unit 62 acquires the unused time initial value L Λ 1 from a step response obtained by inputting a step signal (predetermined input signal) to a model of the control object P having the transfer function G ^. Fig. 7 shows an example of the step response. In the present embodiment, as shown in fig. 7, the dead time initial value acquisition unit 62 acquires, as the dead time initial value L ^ 1, the time from when the step signal is input (time 0 in fig. 7) until the output value exceeds the threshold value X for the step response. The threshold value X is set to a value of a predetermined proportion (for example, 10%) of the convergence value of the step response, for example.
The dead time initial value acquisition unit 62 may acquire, as the dead time initial value L Λ 1, a time from when the step signal is input until the moving average of the output values exceeds the threshold value for the step response.
Further, when a step signal is input to a motor driven in accordance with a torque command, the motor may continue to accelerate to reach an upper speed limit of the motor. Therefore, adjustment of the step signal is required. On the other hand, as described above, the transfer function G Λ of the control object P is obtained and the step response is obtained by inputting the step signal to the model having the transfer function G Λ, whereby the useless time initial value L Λ 1 in the control object P can be obtained without directly inputting the step signal to the control object P. Therefore, the useless time initial value L Λ 1 in the control object P can be easily obtained without adjusting the step signal.
In addition, since the useless time initial value L Λ 1 is obtained as described above, the influence of noise is not easily exhibited in the step response of the model having the transfer function G Λ by performing noise processing in at least one of the process of obtaining the frequency characteristic G of the control object P and the process of estimating the transfer function G Λ. In fig. 8, the measured result of the step response is shown by comparing the measured result with the step response obtained by using the model having the transfer function G Λ as described above. As shown in fig. 8, frequency characteristics with less noise can be obtained. Thus, the useless time initial value L & ltn & gt 1 can be easily obtained according to the step response.
Further, the dead time initial value may be acquired from a step response obtained by inputting a step signal to the control target P. In this case, the time from when the step signal is input until the output value exceeds the threshold value X may be acquired as the initial value of dead time for the obtained step response, or the time from when the step signal is input until the moving average of the output values exceeds the threshold value may be acquired as the initial value of dead time for the obtained step response.
The frequency characteristic acquiring unit 63 obtains a useless time element e using the transfer function G-1 acquired by the transfer function acquiring unit 61 and the useless time initial value L-1 acquired by the useless time initial value acquiring unit 62-L^′1sObtaining G-E obtained by removing useless time elements obtained by using useless time initial values L-E1 from transfer function G-E-L^′1sThe frequency characteristic of (1).
Here, L ^' 1 is, for example, a value satisfying the following relationship. In addition, L ^ 1 may be a value specified as another range with L ^ 1 as a reference.
L＾1min＝L＾1-L＾1/10
L＾1max＝L＾1+L＾1/10
L＾1min≤L＾′1≤L＾1max
The dead time calculation unit 64 obtains L ^' 1 that minimizes the value of the evaluation function J of expression (1).
[ numerical formula 5]
Furthermore, in formula (1), in G ^/e-L^′For the derivation of 1s, G ^ obtained by the transfer function acquisition unit 61 may be used, or the frequency characteristic G obtained by inputting a random signal to the control object P may be used.
Thus, the value of the evaluation function J of the formula (1) can be determined to be the minimum value in L ^ 1 satisfying that L ^ 1min is less than or equal to L ^ 1 and L ^ 1 is less than or equal to L ^ 1 max. By thus obtaining a value which is within a predetermined range with the value of the useless time initial value L Λ 1 as a reference and which minimizes the value of the evaluation function J of expression (1), the useless time of the control object P can be estimated with high accuracy even in the case where the useless time initial value L Λ 1 cannot be obtained with high accuracy.
By obtaining the useless time L Λ '1 in the control target P using the formula (1) as described above, the useless time L Λ' 1 can be obtained with high accuracy.
By obtaining the dead time initial value L Λ 1 as in the present embodiment, it is possible to obtain a dead time initial value closer to the dead time of the control target P. Therefore, the dead time of the control target P can be estimated more quickly than the configuration of embodiment 1.
(operation of dead time estimating apparatus)
Next, the operation of the dead time estimation device 60 having the above-described configuration will be described with reference to the flow shown in fig. 9.
When the flow shown in fig. 9 starts, in step SB1, the transfer function acquisition unit 61 of the dead time estimation device 60 inputs a random signal to the control target P. In the next step SB2, the transfer function acquisition unit 61 measures the frequency characteristic G from the output when the random signal is input to the control target P. Then, in step SB3, the transfer function acquisition unit 61 estimates the transfer function G ^ of the control object P so that the evaluation function J0 of the expression (2) described above is minimized, using the frequency characteristic G.
Next, the dead time initial value acquisition unit 62 inputs a step signal to the model of the control object P having the transfer function G Λ to acquire a step response (step SB 4). Thereafter, the dead time initial value obtaining section 62 obtains the dead time initial value L Λ 1 from the step response (step SB 5). In this case, the dead time initial value acquiring unit 62 acquires, as the dead time initial value L ^ 1, the time from when the step signal is input until the output value exceeds the threshold value for the step response.
In the next step SB6, the frequency characteristic obtaining part 63 obtains the value G/e obtained by removing the useless time elements obtained by using the useless time initial value L/1 from the transfer function G/obtained in the step SB3-L^′Frequency characteristic of 1 s. Here, L ^' 1 is, for example, a value satisfying the following relationship.
L＾1min＝L＾1-L＾1/10
L＾1max＝L＾1+L＾1/10
L＾1min≤L＾′1≤L＾1max
Then, in step SB6, the dead time calculation unit 64 obtains the dead time L Λ 1 in the control object P so that the evaluation function J of the expression (1) described above is minimized.
Thus, the useless time L & ltn & gt 1 of the control object P can be obtained with high precision.
(other embodiments)
Although the embodiments of the present invention have been described above, the above embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiments, and the above-described embodiments can be appropriately modified and implemented without departing from the scope of the present invention.
In the above embodiments, the control device 2 has a differential feedback system. However, the control device may have another control system as long as it is a control system affected by the dead time in the control target.
For example, the control device 102 may have a 2-degree-of-freedom control system shown in fig. 10. The control device 102 has a feed forward loop 120. In the control device 102, an inverse model of the transfer function is used in the feedforward loop 120. Therefore, it is necessary to obtain a transfer function without dead time. Therefore, the control device 102 is required to estimate the dead time with high accuracy to improve the control performance.
Further, in fig. 10, reference 112 is a controller of the feedback system. In addition, the markers 111, 121 are controllers of a feed forward system.
In embodiment 2, the useless time initial value obtaining part 62 obtains the useless time initial value L Λ 1 from a step response obtained by inputting a step signal to a model of the control object P having the transfer function G Λ. However, the dead time initial value acquisition section may acquire the dead time initial value from a ramp response in the model. That is, the dead time initial value acquisition unit may acquire the dead time initial value from the response, and may input any type of signal to the model. Further, considering the accuracy of the obtained dead time initial value, it is preferable to obtain a step response from the model.
In each of the above embodiments, the control object P includes the motor drive circuit 3, the electric motor 4, and the torque detector 5. However, the control target may have any other configuration as long as it has a configuration capable of giving a driving force to the sample, and may include a shaft system having another configuration.
In the above embodiments, the dead time estimating devices 6 and 60 are provided in the test apparatus 1. However, the dead time estimating apparatus may be provided in another apparatus that needs to estimate the dead time, or may be configured separately.
Industrial applicability
The present invention can be used in a dead time estimation device that estimates a dead time of a control target.
Claims (7)
1. A dead time estimating device estimates a dead time of a control target,
the dead time estimating device includes a dead time calculating unit for setting a frequency characteristic of an element obtained by removing a dead time element from a transfer function of the control object to G ^ e-L^′1sAnd a dead time calculation unit for calculating a dead time L ^ 1 where the value of the evaluation function J in the formula (1) is minimum, when a transfer function not including a dead time element of the control object is G ^ and,
2. the dead time estimation device according to claim 1, further comprising:
a dead time initial value acquisition unit that obtains a dead time initial value of the control target; and
a frequency characteristic acquisition unit that obtains the useless time element by using the useless time initial value and obtains a frequency characteristic obtained by removing the useless time element from the transfer function of the control targetThe frequency characteristic of the element(s) is taken as G ^ e-L^′1s。
3. The dead time estimation apparatus according to claim 2,
the dead time calculation unit obtains the dead time L ^' 1 in a predetermined range based on the initial value of the dead time and minimizing the value of the evaluation function J.
4. The dead time estimation apparatus according to claim 2 or 3,
further comprising a transfer function acquisition unit for inputting a signal to the control target and acquiring a transfer function based on a response result of the signal,
the dead time initial value acquiring unit obtains the dead time initial value based on a response signal obtained when a predetermined input signal is input to the control target of the transfer function acquired by the transfer function acquiring unit.
5. The dead time estimation apparatus according to claim 4,
the dead time initial value acquisition unit obtains, as the dead time initial value, a time until the response signal exceeds a predetermined threshold.
6. The dead time estimation apparatus according to claim 4 or 5,
the prescribed input signal is a step signal.
7. A test apparatus is provided with:
a control target that gives a driving force to the sample;
a control device that controls the control object; and
a dead time estimation apparatus as claimed in any one of claims 1 to 6 which outputs the estimated dead time to the control means.
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| JP2019058568A JP7348468B2 (en) | 2019-03-26 | 2019-03-26 | Dead time estimation device and testing device equipped with the same |
| JP2019-058568 | 2019-03-26 |
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| US (1) | US11366432B2 (en) |
| EP (1) | EP3715963B1 (en) |
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| JPH0784611A (en) * | 1993-09-10 | 1995-03-31 | Yamatake Honeywell Co Ltd | controller |
| JPH09305574A (en) * | 1996-05-16 | 1997-11-28 | Yamatake Honeywell Co Ltd | Dead time estimation device |
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| US20200310363A1 (en) | 2020-10-01 |
| EP3715963B1 (en) | 2022-05-04 |
| JP7348468B2 (en) | 2023-09-21 |
| JP2020160715A (en) | 2020-10-01 |
| EP3715963A1 (en) | 2020-09-30 |
| CN111752146B (en) | 2024-06-11 |
| US11366432B2 (en) | 2022-06-21 |
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